What good is HTML5 audio/video support without mandatory Ogg? It seems that (thanks to Nokia) we'll see the the same old "each browser does it its own way". Firefox will go with Ogg, IE will pretty surely go with WMV/WMA, and Apple, it seems, will go with MPEG4. The obvious outcome is that Flash/FLV will continue being used because it's the common denominator. And that sucks...

Webkit is open source, isn't it?

Won't some interested Webkit user (possibly Google Chrome) want to make sure that webkit can compete with this? ...

"Another impressive feature that Web application developers will be able to take advantage of in Firefox 3.1 is support for worker threads, which provide support for concurrent execution in JavaScript. Worker threads will make it possible to perform complex computations in the background, so that the browser and Web application don't hang or become unresponsive.

The HTML 5 video element will also arrive in Firefox 3.1. This will allow video content to be embedded directly in Web pages, controlled with JavaScript, and manipulated through the DOM. It's a major step forward for rich media content on the Web. Firefox 3.1 will ship with built-in support for the Ogg Vorbis and Theora formats—open audio and video codecs that are believed to be unencumbered by patents. The actual codec implementations are integrated directly into the browser itself, so content in those formats will be playable without requiring any external components or plugins.

Blizzard says that Mozilla aims to encourage an explosion of creativity around video that will mirror the kind of uninhibited innovation that has flourished in the Web's inclusive standards-base ecosystem. Mozilla is actively contributing funding to Ogg development efforts to help accelerate the process. He says that Theora, which is used by Wikipedia, has the potential to achieve quality comparable to MPEG4. High definition video, however, will require the Dirac format, which could eventually be included in future versions of Firefox when it matures."

If Firefox can do all this, and then soon after (or even perhaps in the same timeframe) so too can Opera and Google Chrome, then Safari is going to have to implement it also in order to stay relevant.

We are right now not far away from the tipping point when Firefox + Google Chrome + Safari + Opera represents more than 50% of all web browsers. When we do get to that point, and they can all play rich content (in Vorbis, Theora and Dirac) straight out of box ... then we may hopefully finally see the back of browser-based lock-in to web content start to be broken.

FTA:

To illuminate the possibilities that are unlocked by these new features, Blizzard showed several technical demos. One of the demos used the HTML 5 video element to display a space shuttle launch. As the video played, JavaScript code running on the page used the video time index to retrieve launch data from a JavaScript array and draw graphs that show the shuttle's speed and altitude increasing during the launch.

The most impressive demo that he showed during his presentation used JavaScript in worker threads to programmatically detect motion in a playing video. This one has to be seen to be believed